This has been on our to-do list for quite some time. I am not sure who originally posted about Elephant Toothpaste, but I've seen it around several places and have been wanting to try it for several months now. With a name like Elephant Toothpaste - how could it not be awesome, right? Anyway, I finally got around to shopping for the necessary ingredients a week ago and oh my goodness am I glad I did because this was such a fun demonstration!!! When it comes to science at our house I mainly focus on child-led explorations, challenges, and experiments (you can find over 100 of those in our new science book), but I also like to throw in a few fun demonstrations such as this one here and there. These demos are famous for a reason - they're pretty remarkable!

First off, I had S prep the yeast. She measured out the correct amount and added it to the warm water and stirred. I gave it a few stirs at the end to get out one or two yeast clumps, but this is a great step to involve your child in.

Next I had S put on her safety goggles! She is so darn cute in them, I find myself inventing new activities where they might come in handy just to see *this* adorable face. Hahaha. We scored these kid-sized safety goggles at Lowes (a US hardware store) for something like $2!

I measured and added the peroxide myself, and allowed S to add the squeezes of dish soap, Colorations Liquid Watercolors, and some plastic glitter (of course! If you'd also like to add glitter, be sure to add plastic glitter vs. metal-based glitter as peroxide should not be used with metal glitter). Once I'd carefully swirled the ingredients together myself, I had S add the yeast through a funnel. I stayed within arm's reach to be sure that the bottle wasn't going to tip on her. I also used a short bottle with a wide base (this particular bottle was from a Hint drink) to increase the stability; however, any narrow necked bottle will work for this experiment - even an empty plastic water bottle. If you choose to let your child add the yeast, be sure you are close by ready to catch the bottle should it accidentally tip. :) As soon as you add the yeast, the reaction starts! The yeast acts as a catalyst and speeds up the hydrogen peroxide's release of oxygen gas --- when that gas hits the soap it makes a crazy fun amount of fluffy foam! Below you can see it already foaming up even though S is still adding the yeast!

Immediately remove your funnel and watch the crazy eruption of giant foam spill out of your bottle! The foam is totally safe to touch (and so soft and puffy!) - the peroxide (H2O2) is broken down in the reaction - so there isn't any left. It leaves behind water (H20) and oxygen (O2) only - so again, completely safe to handle.

It all happens quickly and is quite the sight!!! The reaction is exothermic, meaning that it gives off heat. You can have your child touch the bottle after the reaction has taken place and they can feel the warmth radiating out. S was so surprised!

Once the foam has stopped erupting, I removed the bottle and S played with some dragons and dinos in the foam.

After awhile we decided we needed to do it just ooooone more time and went with pink this time. It was still the coolest thing ever!!!

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To make your own Elephant's Toothpaste you will need:

Close adult supervision

Safety goggles for your child if they are going to be involved in any mixing/pouring

*6% (20 volume) Hydrogen Peroxide
is a bit of a specialty item - you will need to find a nearby Beauty Salon Supply shop (or click the link to purchase it on Amazon). The reaction will still work with 3% Hydrogen Peroxide (the kind you can buy at a drugstore or grocery), but it is much less dramatic.

Measure 1 teaspoon of yeast (half of one of those little pouches it comes in) into 2 Tablespoons of very warm water. Mix well.

Into your narrow-necked bottle, add 1/2 cup of 6% (20 volume) Hydrogen Peroxide
(I recommend an adult does this step for safety), any coloring you would like (Colorations Liquid Watercolors or Food Coloring), glitter (if you'd like), and a few squirts of Dawn Dish Soap. Swirl it all carefully (this is another job I'd recommend an adult do for safety).

Place your bottle in a container to catch the mountain of foam (we used a glass baking dish), then add the yeast mixture through a funnel. Quickly remove the funnel and enjoy the show!

UPDATE: We did a family science demonstration with Elephant Toothpaste on a larger scale - The experiment below is to be performed by adults only and children should stand at a safe distance. Please follow all directions on the Hydrogen Peroxide bottle and exercise caution when handling as the concentration used will bleach clothes and can irritate/burn skin.

Adult Run Demonstration:

Take an empty 2 Liter Soda bottle and using caution add 1 cup of 40 Volume (12%) Hydrogen Peroxide
using a funnel. Add a few squirts of Dawn Dish Soap. Swirl gently. Take one full packet of Dry Active Yeast and add it to 4 Tablespoons of very warm water. Stir well. Place 2 Liter bottle with Hydrogen Peroxide and Soap in a container and using a funnel add yeast mixture. Immediately remove funnel and step back and watch the show! The foam and bottle will be VERY warm - so please have an adult cautiously check the temperature before allowing children to play in the foam. As with the above experiment, the soap foam is soap foam - no peroxide is left - so it is safe to handle once it has cooled.

My awesome friend Jeanette at Artchoo created an elephant-sized toothbrush craft after seeing this. It's HILARIOUS. You can check out her Elephant Toothbrush here!

All activities here are activities I feel are safe for my own children. As your child's parents/guardians, you will need to decide what you feel is safe for your family. I always encourage contacting your child's pediatrician for guidance if you are not sure about the safety/age appropriateness of an activity. All activities on this blog are intended to be performed with adult supervision. Appropriate and reasonable caution should be used when activities call for the use of materials that could potentially be harmful, such as scissors, or items that could present a choking risk (small items), or a drowning risk (water activities), and with introducing a new food/ingredient to a child (allergies). Observe caution and safety at all times. The author and blog disclaim liability for any damage, mishap, or injury that may occur from engaging in any of these activities on this blog.

Comments

What am I doing wrong that my toothpaste is so slow? It still comes out and looks like yours but it's really sllllooooww. Could it be too much Dawn? I have everything else with the right measurements. Either way this was FUN!!!!!! Thank you for posting!!

Hi Connie! Hm, I would suspect that it was either old yeast (like not active enough) or you didn't get strong enough peroxide (the 6% we used can't be bought in a grocery store - it is kind of a specialty thing) or that the peroxide was old? The reaction with the gas should be fast - and the things that react to make the gas are the yeast and the peroxide - so that would be my best guess? Glad you still had fun! :)

I am determined to find a way to do this in my life science class. Maybe a lesson on yeast and inference (what prior knowledge do you have about these ingredients that will help you guess what happens when I mix them together?)... Oh joy! This is going to be fun!

I teach HS Biology - It's very easily applied to enzymes and chemical reactions. Have the kids determine what enzyme the yeast make (catalase) and why most organisms produce it (peroxide is a toxic metabolic byproduct), as well as the chemical reaction involved. You can use the eruption as a great motivator and the entire lesson can be inquiry based.

I would assume so - my understanding is that the yeast acts as a catalyst. There would then be an upper bound at which it would only be so effective, but less yeast should cause a slower reaction. I hope that helps!

Lower concentrations of peroxide are fine to touch, as the handling time (time in contact with the skin) is relatively low. Having run this experiment at a university level with 30% hydrogen peroxide, and potassium iodide in place of the yeast, safety gloves need to be used both in the preparation stage (hydrogen peroxide is highly corrosive), and during the clean-up stage. Though much of the peroxide has reacted and converted to water and oxygen, the force in which the foam is shot through the container does carry peroxide with it. That being said, at this strength as long as you wash your hands thoroughly afterwards, the most that will potentially happen is the hair on the back of your hands becomes very slightly lighter.

It can be a bit tricky to find the 6%. We found ours at a local beauty supply shop (it's used by hair salons to bleach hair), but you can also buy it on Amazon through the link above. I'd call before going to any stores, just because it can be a specialty item.

Two things to note,1. Do not add glitter as recommended by the author as at even 6%, hydrogen peroxide is a strong oxidizer which should not be combined with certain metals.2. Make sure you stay away from 'antibacterial' dish washing liquids as they often contain triclosan (which is chlorine based and should not be combined with hydrogen perodixe)

Tried it today with the $0.88 Walmart hydrogen peroxide - definitely does not produce as sturdy a foam as in your pictures, but my little guy (almost three) has been playing for half an hour! We tried yellow, blue, and red. He is happily playing away in a a baking pan of seaweed-green looking foam! Thanks for the idea!

Hey, I work in a special needs school and am looking at doing this activity for science week. How much yeast and stuff should I be putting in. You said a pack but how big a pack??? oh and what "dawn" soap should I get, I don't know this brand and the amazon link showed quite a few :P If I am planning on doing 3-4 bottles. Using your links, how much stuff should I be buying :) Thanks and sorry about all the questions

Hi! Yeast is usually sold in four little packs all stitched together in the grocery store. Each pack contains 1/4 oz. And any scent of Dawn is fine as long as it's not antibacterial -- I just bought the cheapest type of Dawn at our grocery store. :) If you only want to make 4 bottles, one set of four envelopes of yeast and one bottle of Dawn would be more than enough. Hope that helps!

If anyone is reading this now, I just got a 1-gallon jug of peroxide at our local Sally Beauty Supply for $4.99!! It was on sale, so it was actually cheaper than the 1/2 gallon and perhaps even the one smaller than that! I guess I'll be doing this experiment a lot!

A question about the Dawn - can you use other dish soap? I forgot to buy Dawn and I normally use other stuff for dishes.

I am going to try this with a bunch of kids for my son's mad scientist birthday party. I am thinking of having the peroxide/soap in the bottles already and prepping the yeast/water ahead of time and putting it in little paper cups. then when the time is right the children can pour in the color they choose and then the yeast mix. do you think this will work with having the peroxide and yeast sitting in open containers? or should it be done all at once?

SO fun! You may have some trouble pre-mixing the yeast as if it cools/dries too much it may inactivate some of the yeast. Mixing the soap and peroxide ahead of time is perfect and I think I'd measure out the dry yeast and then pour warm water into the cups for the children when you were ready to go to ensure the yeast stays awake and active enough for a good reaction. Hope that helps! And happy birthday to your son!!!

Is it Benzoyl Peroxide that you have? That's a different chemical than the one we need for this reaction - hydrogen peroxide. As far as I know hydrogen peroxide is only available in a liquid. Hope that helps!!

It does say Hydrogen Peroxide in the ingredients list. I was more considering whether all of the extra stuff in it could potentially prevent the reaction, or that the viscosity might be too slow the reaction. It's ok, we'll just go with the 3% :) Thanks for replying!

Oh how interesting! I would worry about the viscosity, the amount you'd have to use (if it's a cream, there's likely just a small amount of hydrogen peroxide added since it's a liquid), and also whether or not you'd inadvertently create a bad chemical by accident (with the other cream ingredients reacting in a way we don't anticipate).